Structural Models of Ligand-Bound Sodium Channels.

Area of Science:

• Structural biology
• Pharmacology
• Neuroscience

Background:

• Voltage-gated sodium channels (VGSCs) are crucial for neuronal excitability.
• Understanding their structure is key to developing therapeutics for pain and neurological disorders.
• Existing structural data from P-loop channels inform models of mammalian VGSCs.

Purpose of the Study:

• To elaborate homology models of mammalian voltage-gated sodium channels.
• To integrate experimental data and facilitate drug design for VGSC-targeting ligands.
• To summarize existing models incorporating various drugs and neurotoxins.

Main Methods:

• Utilizing X-ray and cryo-electron microscopy (cryo-EM) structures of tetrameric and pseudo-tetrameric P-loop channels.
• Developing homology models of mammalian voltage-gated sodium channels.
• Integrating experimental data into structural models.

Main Results:

• Models of sodium channels complexed with local anesthetics, anticonvulsants, and antiarrhythmics were outlined.
• Models incorporating neurotoxins like tetrodotoxin, mu-conotoxins, batrachotoxin, scorpion toxins, and insecticides were summarized.
• The potential role of sodium ions in ligand action was discussed.

Conclusions:

• Homology models are valuable tools for understanding drug and toxin interactions with voltage-gated sodium channels.
• These models can guide experimental planning and accelerate the design of novel therapeutics.
• The models provide insights into the mechanisms of action for various sodium channel modulators.